Difference Between Capacitor Start And Capacitor Run Induction Motor

5 min read Jun 26, 2024
Difference Between Capacitor Start And Capacitor Run Induction Motor

Difference between Capacitor Start and Capacitor Run Induction Motor

Induction motors are widely used in various industrial and domestic applications. They are simple, rugged, and reliable, making them a popular choice for many applications. However, they have some limitations, such as low starting torque and low power factor. To overcome these limitations, capacitors are used in induction motors. There are two types of capacitor-based induction motors: capacitor start and capacitor run induction motors. In this article, we will discuss the differences between these two types of motors.

What is a Capacitor Start Induction Motor?

A capacitor start induction motor is a type of single-phase induction motor that uses a capacitor to improve its starting torque. During starting, the capacitor is connected in series with the auxiliary winding to create a rotating magnetic field, which produces a high starting torque. Once the motor reaches a certain speed, the capacitor is disconnected, and the motor runs as a normal single-phase induction motor.

Advantages of Capacitor Start Induction Motor:

  • High starting torque
  • Simple and cost-effective design
  • Widely used in applications such as refrigerators, air conditioners, and washing machines

What is a Capacitor Run Induction Motor?

A capacitor run induction motor is a type of single-phase induction motor that uses a capacitor to improve its running performance. In this type of motor, the capacitor is connected in series with the auxiliary winding during both starting and running conditions. The capacitor helps to improve the power factor, reduce the current, and increase the efficiency of the motor.

Advantages of Capacitor Run Induction Motor:

  • Improved power factor
  • Increased efficiency
  • Reduced current
  • Widely used in applications such as fans, pumps, and conveyor systems

Key Differences between Capacitor Start and Capacitor Run Induction Motor:

Starting Torque

  • Capacitor start induction motor: High starting torque due to the capacitor connected in series with the auxiliary winding during starting.
  • Capacitor run induction motor: Moderate starting torque, but improved running performance due to the capacitor connected in series with the auxiliary winding during both starting and running conditions.

Capacitor Connection

  • Capacitor start induction motor: Capacitor is connected in series with the auxiliary winding only during starting.
  • Capacitor run induction motor: Capacitor is connected in series with the auxiliary winding during both starting and running conditions.

Running Performance

  • Capacitor start induction motor: Running performance is similar to a normal single-phase induction motor.
  • Capacitor run induction motor: Improved running performance due to the capacitor, which improves the power factor, reduces the current, and increases the efficiency of the motor.

Applications

  • Capacitor start induction motor: Widely used in applications such as refrigerators, air conditioners, and washing machines.
  • Capacitor run induction motor: Widely used in applications such as fans, pumps, and conveyor systems.

Conclusion

In conclusion, capacitor start and capacitor run induction motors are two types of single-phase induction motors that use capacitors to improve their performance. While capacitor start induction motors are designed to provide high starting torque, capacitor run induction motors are designed to improve running performance. Understanding the differences between these two types of motors is essential to select the right motor for a specific application.